I have a 2001 Z06 that has been giving me fits with the clutch master cylinder. I am an oldish fellow and pick and choose what servicework I will do. About a year ago I had a friend that is a retired master mechanic that worked for a Chevy dealer here for about 30 years. My clutch pedal wasn’t returning fully and wouldn’t disengage fully. I bought a replacement master cylinder from Orielly and my buddy installed it. Seemed to work ok for a few days. I went back to Orielly four more times due to the same symptom re-occurring. My buddy said it was probably the throw out bearing and since he doesn’t have a lift he couldn’t help me further. I went to a transmission shop that I had used multiple time on the company fleet that I supported. I brought him another warranty replacement from Orielly and he replaced it. Same results on the 10 mile drive home. I requested that he buy a replacement from Rock Auto instead he got another warranty replacement from Orielly. He also said he also replaced the throw out bearing while he was in there. The bearing was from Chevy. What the heck is going on? The brake fluid stays at the same level all the time. When I back it out of the garage, after being in there a couple days, the clutch pedal doesn’t come back where it belongs and won’t disengage so I shut the motor off and then i can shift it into first and drive off. I pump it multiple times before I get to the next intersection. Always being vigilant to shift into neutral and let the clutch out after pumping it vigorously. But three miles later I have to do the same thing over. I think that makes four or five clutch master cylinders so far. What the hell is wrong? I’m using Dot 5 brake fluid. Help please!!!

 

If you are using Dot 5, it is not compatible with your clutches Dot 3 hydraulic system.

 

He said he replaced the throw out bearing "while he was in there"? The clutch master is not in close proximity to the slave.

 

The entire drivetrain needs to be removed to replace the slave/throw out bearing. Mine went bad on my 30k mile car just from age. The hydraulics on these cars are not great so your issue is probably the slave and not the master that you have been replacing.

 

Sorry to be asking questions rather that trying to answer yours but some of the information you provided needs more detail.

First, the type of brake fluid you uses. Our systems require DOT 3, or DOT 4 which is compatible with DOT 3. If you did use DOT 5, they are chemically incompatible and will probably ruin the seals in the master and slave cylinders. Perhaps you meant to write DOT 5.1 which is chemically compatible with our DOT 3 systems.

Second, when your write "throw out bearing" which you said was replaced by the transmission shop, we have to assume you mean the clutch slave cylinder. This is a very labor intensive job where, as Kubs has written, requires that you drop the entire drivetrain. Unless you clutch was pristine or recently replaced, it is hard to imagine a shop just replacing the slave cylinder because it is so many hours of labor when dropping the drivetrain. Did it cost you $1000? $2000? more? Do you have a bill from the transmission shop?

 

I typed that message while at church waiting for it to start yesterday. Today I checked the brake fluid when I saw your message. Thankfully there is only a 1/2 cup of DOT 3 fluid left of “Prestone Brake Fluid”. Good news right?

I had the clutch replaced 20,000 miles ago and they put a new master and slave and TO bearing at the same time. I took it to them because of diff gear howling. I does have a braided stainless bleed hose under the hood this making bleeding pretty easy.

Any further observations or recommendations. Thank you for your reply!

 

Moved to C5 Tech for some answers.

 

Is the clutch pedal return spring still in place? If not, reinstall it.

 

You said you have a remote bleeder. Was the entire system flushed to make sure air was purged? No leaks in the floor, yes?

 

The return spring will actually hold the pedal to the floor at full travel. Once the spring moves over center, it holds the pedal down vs bring it back up. I have been tracking my car with zero spring on the pedal for years without issue.

 

Yes, but it returns the pedal back to the upright position when it moves over center towards the resting position. If the pedal does not fully return to the resting position, the clutch master cylinder will not fill completely with hydraulic fluid from the reservoir. Are you running an OEM clutch without the return spring?

 

Yes I ran the OE clutch without the return spring. When I put a new OE clutch in with a Fidanza flywheel I kept the return spring off. When I put a Tick master cylinder in I kept the return spring off. When I replaced the OE clutch with an ACT unit I also, kept the return spring off.

 

Interesting, I've never removed it on the three C5s I've owned. My first two C5s were auto crossed and HPDE driven regularly, I never had an issue with the clutch pedal return spring.

 

This is not the Corvette ownership experience we strive for, Brian. Our team would like the opportunity to learn more about the clutch concern on your Z06 and investigate ways we can potentially assist. When you get the chance, please send us an email to socialmedia@gm.com. Be sure to include your Username and Forum name in the subject line, then provide additional details about your experience in the body of the email. We look forward to your contact.

 

Wow! Customer Care wanting to hear about a problem with a 23 year old car with a replacement clutch?!? Brian, please let us know if they assist with improving your “ownership experience”.

Good on you Customer Care for reaching out.